Device and method for monitoring a brake-applying electromechanical device for vehicle brakes

Abstract

The invention concerns a device and a method for monitoring an electromechanical brake-applying device designed for motor vehicle brakes. Said electromechanical brake-applying device comprises the following elements: a control member comprising an electric motor provided with electric supply; preferably a cylinder with accumulator including a spring which can be tensioned by the control member and serving to actuate a plunger to apply and release the vehicle brake. The monitoring device has a detecting unit for establishing an intensity and/or voltage curve of the current flowing in the electric supply whereof the output is connected to an evaluating unit for comparing the value of said intensity and/or voltage curve with previously stored threshold values and/or previously stored threshold value characteristic.

What is claimed is:  
     
       1. Device for monitoring an electro-mechanical brake application device for a vehicle brake, the electro-mechanical brake application device having a drive which comprises an electric motor with a current supply, and a spring-loaded cylinder having a spring, which is tensionable by the drive, for actuating a plunger for the application and release of the vehicle brake, the device comprising: 
       a detecting device for detecting the current and/or voltage curve in the current supply;  
       an evaluating unit connected to an output of the detecting device, the evaluating unit comparing the detected current and/or voltage curve with previously stored desired values and/or a previously stored desired-value characteristic; and  
       wherein the detecting device has a sensor, which is assigned to the current supply, for sensing the current or voltage curve applied in a feed line to the electric motor.  
     
     
       2. Monitoring device according to  claim 1 , wherein the evaluating unit is designed for comparing the detected current and/or voltage curve with the previously stored desired-value characteristic in a generator operation of the electric motor. 
     
     
       3. Monitoring device according to  claim 2 , wherein the evaluating unit is designed for comparing the detected current and/or voltage curve with the previously stored desired-value characteristic in a motor operation of the electric motor. 
     
     
       4. Monitoring device according to  claim 2 , wherein the evaluating unit is designed for emitting a defect message in an event of a limit-value-exceeding deviation from the desired-value characteristic. 
     
     
       5. Monitoring device according to  claim 2 , wherein the evaluating unit is designed for initiating a defect correction in the event of a limit-value-exceeding deviation from the desired-value characteristic. 
     
     
       6. Monitoring device according to  claim 2 , wherein the brake application device has a transmission which is assigned to the electric motor and has a spindle device for tensioning the spring. 
     
     
       7. Monitoring device according to  claim 1 , wherein the evaluating unit is designed for comparing the detected current and/or voltage curve with the previously stored desired-value characteristic in a motor operation of the electric motor. 
     
     
       8. Monitoring device according to  claim 7 , wherein the evaluating unit is designed for emitting a defect message in an event of a limit-value-exceeding deviation from the desired-value characteristic. 
     
     
       9. Monitoring device according to  claim 7 , wherein the evaluating unit is designed for initiating a defect correction in the event of a limit-value-exceeding deviation from the desired-value characteristic. 
     
     
       10. Monitoring device according to clam  7 , wherein the brake application device has a transmission which is assigned to the electric motor and has a spindle device for tensioning the spring. 
     
     
       11. Monitoring device according to  claim 1 , wherein the evaluating unit is designed for emitting a detect message in an event of a limit-value-exceeding deviation from the desired-value characteristic. 
     
     
       12. Monitoring device according to  claim 11 , wherein the evaluating unit is designed for initiating a defect correction in the event of a limit-value-exceeding deviation from the desired-value characteristic. 
     
     
       13. Monitoring device according to  claim 11 , wherein the brake application device has a transmission which is assigned to the electric motor and has a spindle device for tensioning the spring. 
     
     
       14. Monitoring device according to  claim 1 , wherein the evaluating unit is designed for initiating a defect correction in the event of a limit-value-exceeding deviation from the desired-value characteristic. 
     
     
       15. Monitoring device according to  claim 1 , wherein the brake application device has a transmission which is assigned to the electric motor and has a spindle device for tensioning the spring. 
     
     
       16. Monitoring device according to  claim 15 , further comprising a displacement transducer arranged on the spindle device. 
     
     
       17. Monitoring device according to  claim 16 , wherein the displacement transducer is constructed as a distance sensor. 
     
     
       18. Monitoring device according to  claim 16 , wherein the displacement transducer is constructed as a rotation transducer. 
     
     
       19. Monitoring device according to  claim 1 , wherein the application device has a holding device which comprises a mechanically and/or electro-magnetically releasable brake. 
     
     
       20. Method of monitoring an electro-mechanical brake application device for a vehicle brake having a monitoring device comprising a detecting device for detecting the current and/or voltage curve in a current supply, an evaluating unit connected to an output of the detecting device, said evaluating unit comparing the detected current and/or voltage curve with previously stored desired values and/or a previously stored desired-value characteristic, and wherein the detecting device has a sensor, which is assigned to the current supply, for sensing the current or voltage curve applied in a feed line to an electric motor of the electro-mechanical brake application device, the method comprising the acts of: 
       monitoring, via the detection device, a current and voltage curve in a current supply in a generator operation and/or in a motor operation of the electric motor;  
       comparing, via the evaluating unit, the monitored current and voltage curve with previously stored desired values or with a previously stored desired value characteristic; and  
       in an event of an occurrence of deviations from the previously stored desired value or the previously stored desired-value characteristic, generating a defect signal.